Personally I did it to sort of give my fictional country a unique identity. Since its like on a different planet, i tried not to use any rootes from already existing languages but I later decided (later being 3 months ago in the 5 years of my language's existance) that in my fictional universe a civilization that lived thousands of years ago supposedly had dominated parts of earth and thus their language gave birth to both Proto-Indo European and my own language. So basically there's my fictional 'base root' (say for number one)
húndë, which gave birth to both the Proto-Indo European
hoino, the Ancient Greek
héna (Modern Greek
éna), the Latin
unus, the Hindu
ek but also the word for '1' in my fictional language which is
ćë.
For me languages are a way to enhance my storyline and historical background of the cultures I've created rather than just a set of phonetics and I try to portray the culture I'm working on (my Empire has a highly complex language with 16 different tenses and 4 different number) on their language.
Thats how I do it
